Berlinia (Berlinia korupensis)

Berlinia korupensis, a giant rainforest tree species, is limited to a single plot of land within Korup National Park in Cameroon.

Only 17 individuals of Berlinia korupensis are known to exist.

Berlinia korupensis has a dramatic method of seed dispersal, involving the sudden explosion of seed pods.

With a trunk of nearly 1 m in diameter, Berlinia korupensis can grow to an impressive height of more than 40 m.

Berlinia korupensis has yet to be formally classified on the IUCN Red List, but has been provisionally assessed as being Critically Endangered (CR) using the IUCN Red List Criteria (1).

A giant rainforest tree, Berlinia korupensis can grow to a towering 40 metres or more in height (3), with its crown of branches and leaves creating a half-sphere of between 30 and 35 metres in diameter (1) (3).

Despite its impressive stature, Berlinia korupensis was first noticed by scientists as recently as 2003. This gigantic tree species was initially identified as being Berlinia confusa, before a thorough examination of its flowers and of photographs of the tree in 2005 revealed that it was a species new to science (1).

Berlinia korupensis is a member of the Leguminosae, better known as the pea family (4), and is one of more than 100 new plant species discovered in Cameroon by scientists from the Royal Botanic Gardens, Kew, since the mid-1990s (2). It is named after Korup National Park in Cameroon, within which all known individuals of this species are found (1) (2) (3), to emphasise the park’s importance in biodiversity conservation (3).

Berlinia korupensis has a trunk of nearly 100 centimetres in diameter (3), which is supported by triangular buttresses up to 30 centimetres thick and up to 150 centimetres in height. This species is covered in striking, light whitish-brown bark, which is smooth but often flaky. The flakes detach from the bark in groups, leaving behind shallow scars which interestingly form an almost concentric pattern (1) (3).

This gigantic tree species has feather-like leaves (1), and produces large, showy white flowers (3) (4). These stunning flowers are composed of five petals, one of which is much longer and wider than the other four (1) (3). The flowers of Berlinia korupensis are grouped into clusters of two or three racemes, which are inflorescences in which each individual flower has a distinct stalk but is attached to a central stem (1). Berlinia korupensis can be distinguished from other species within its genus by this different petal arrangement (1).

This rainforest giant produces large, flat, oblong fruit pods (3), measuring over 30 centimetres long (3) (4) and about 9 centimetres wide (3). Although the seeds of Berlinia korupensis have yet to be observed, each pod is thought to contain between one and four seeds (1) (3).

Endemic to the Southwest Province of Cameroon (3), Berlinia korupensis is only known from the southern part of Korup National Park (1), where it is one of the rarest tree species (3).

The patch of habitat in which Berlinia korupensis is found consists of lowland primary rainforest with well-drained, sandy soil, at an elevation of about 100 metres (1) (3). This species occurs on flat or slightly sloping ground, and generally avoids areas immediately adjacent to streams or gullies which are at risk of becoming temporarily flooded (1).

The region in which Berlinia korupensis is found has a strongly seasonal climate (1), receiving an average of 503 centimetres of rainfall each year (3), with a distinct dry season between December and February (1).

While there is relatively little information available on Berlinia korupensis, its flowers are reported to be hermaphroditic (1), and this species is known to have a rather dramatic mode of dispersing its seeds (1) (3).

As in all other Berlinia species, the seeds of Berlinia korupensis are contained within a pod, which begins to dry out when exposed to sunshine or dry air. Interestingly, the two parts of the pod, known as ‘valves’, are predisposed to curling up in different directions as they dry, and while a corky connecting layer initially keeps the two valves attached, the tension this creates eventually becomes too great. The pod splits open as the two valves twist rapidly in opposite directions, ejecting the seeds with great force and speed. While some of these seeds drop straight down underneath the crown of the parent tree, others may disperse further (1), reaching a maximum distance of about 50 metres (1) (4).

Although impressive, this mode of dispersal is still limiting for the species, and is thought to be the reason why this rainforest giant forms groves rather than being widely distributed. It is not known whether other methods, such as animals or rivers, also aid in the dispersal of Berlinia korupensis (1).

Berlinia korupensis has been provisionally assessed as Critically Endangered due to its small and restricted population (1), which consists of just 17 known individuals (3). It has also been identified as being at risk from the human pressures placed on Korup National Park (4) (5), including poaching (3). As poaching activities gradually diminish the animal population within the park, the ecology of the vegetation is altered, and this may impact upon Berlinia korupensis (3).

There are no known conservation measures in place which specifically target Berlinia korupensis. However, this impressive rainforest species may be provided some protection as a result of its occurrence within Korup National Park, which is both a protected area and a World Heritage Site (3).

While Berlinia korupensis is not currently in cultivation at Royal Botanic Gardens, Kew, there are preserved specimens of this species housed within the Kew Herbarium as well as within seven other herbaria worldwide, including two in Cameroon (3).

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact: arkive@wildscreen.org.uk

Biodiversity: short for biological diversity, biodiversity is a term used to define the great diversity of life on earth, or more specifically, in a particular habitat or ecosystem.

Buttress: the flared base of certain tree trunks.

Endemic: a species or taxonomic group that is only found in one particular country or geographic area.

Genus: a category used in taxonomy, which is below ‘family’ and above ‘species’. A genus tends to contain species that have characteristics in common. The genus forms the first part of a ‘binomial’ Latin species name; the second part is the specific name.

Hermaphroditic: possessing both male and female sex organs.

Inflorescence: the reproductive shoot of a plant, which bears a group or cluster of flowers.

Primary rainforest: rainforest that has remained undisturbed for a long time and has reached a mature condition.

Raceme: an inflorescence (the flower-bearing reproductive shoot of a plant) in which the individual flowers all have distinct stalks and are attached to a central stem. The flowers at the base open first, and new flowers are produced at the tip as the shoot grows.